6,847 research outputs found
On the AJ Conjecture for Knots
No full textWe confirm the AJ conjecture [Ga2] that relates the A-polynomial and the colored Jones polynomial for hyperbolic knots satisfying certain conditions. In particular, we show that the conjecture holds true for some classes of two-bridge knots and pretzel knots. This extends the result of the first author in [Le2], who established the AJ conjecture for a large class of two-bridge knots, including all twist knots. Along the way, we explicitly calculate the universal SL₂(C)-character ring of the knot group of the (−2, 3, 2n + 1)-pretzel knot, and show it is reduced for all integers n
A review of recent studies on malondialdehyde as a toxic molecule and a biological marker of oxidative stress
No full textAim: Of the many biological targets of oxidative stress, lipids are the most involved class of biomolecules. Lipid oxidation gives rise to a number of secondary products. Malondialdehyde (MDA) is the principal and most studied product of polyunsaturated fatty acid peroxidation. This aldehyde is a highly toxic molecule and should be considered as more than just a marker of lipid peroxidation. Its interaction with DNA and proteins has often been referred to as potentially mutagenic and atherogenic. This review is intended to briefly describe the physiological origin of MDA, to highlight its toxicity, describe and comment on the most recent methods of detection and discuss its occurrence and significance in pathology. Data synthesis: In vivo origin as well as reactivity and consequent toxicity of MDA are reviewed. The most recent and improved procedures for the evaluation of MDA in biological fluids are described and discussed. The evidence of the occurrence of increased MDA levels in pathology is described. Conclusions: In the assessment of MDA, the most common methods of detection are insufficiently sensitive and disturbed by interference coming from related species or overestimation derived from stressing analysis conditions. Moreover, no recent nutritional or medical trials report the use of one of the new and more reliable methods, some of which are undoubtedly accessible to virtually all the laboratories provided with a common HPLC or a spectrofluorimeter
HPLC-MSn analysis of phenolic compounds and purine alkaloids in green and black tea
No full textTea is a complex mixture containing a range of compounds from simple phenolics to complex thearubigins, many of which have well-recognized antioxidant properties. This paper describes the application of high-performance liquid chromatography-mass spectrometry (HPLC-MSn) methods for the rapid and routine analysis of more than 30 phenolics in tea. Green and black tea infusions were injected directly onto a reversed phase HPLC column, and the phenolics eluted using two different mobile phase gradients, one optimized to resolve catechin derivatives and the other, flavonols and theaflavins. Compounds, identified on the basis of their retention time, absorbance spectrum, and MS fragmentation pattern, included (+)-catechin, (-)-epicatechin, theaflavin and their various gallate derivatives, quercetin and kaempferol mono-, di-, and triglycosides, quinic acid esters of gallic acid and hydroxycinnamates, and the purine alkaloids, caffeine and theobromine
A comprehensive individual patient data meta-analysis of the effects of cardiac contractility modulation on functional capacity and heart failure-related quality of life
No full textAims: Cardiac contractility modulation, also referred to as CCMTM, has emerged as a promising device treatment for heart failure (HF) in patients not indicated for cardiac resynchronization therapy. We performed a comprehensive individual patient data meta-analysis of all non-confounded prospective randomized controlled trials of CCM vs. control that have measured functional capacity and/or quality of life questionnaires in patients with HF.
Methods and results: The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE were searched in January 2020 to identify eligible randomized controlled trials. We also asked the sole manufacturer of the device for their list of known trials. Primary outcomes of interest were peak oxygen consumption (peak VO2 ), 6 min walk test distance, and quality of life measured by Minnesota Living with Heart Failure Questionnaire (MLWHFQ), and all data were received as individual patient and individual time point data-points. Mean differences and 95% confidence intervals (CIs) were calculated for continuous data using a fixed-effects model. Five trials were identified, four randomized studies enrolling 801 participants for all endpoints of interest, and for peak VO2 alone (n = 60), there was an additional single arm non-randomized trial (FIX-HF-5C2) with a prospective comparison of its 24 week peak VO2 data compared with the control group of the FIX-HF-5C control patients. Pooled analysis showed that, compared with control, CCM significantly improved peak VO2 (mean difference +0.93, 95% CI 0.56 to 1.30 mL/kg/min, P < 0.00001), 6 min walk test distance (mean difference +17.97, 95% CI 5.48 to 30.46 m, P = 0.005), and quality of life measured by MLWHFQ (mean difference -7.85, 95% CI -10.76 to -4.94, P < 0.00001). As a sensitivity analysis, we excluded the FIX-HF-5C2 trial (only relevant for peak VO2 ), and the result was similar, mean difference +0.65, 95% CI 0.21 to 1.08 mL/kg/min, P = 0.004.
Conclusions: This comprehensive meta-analysis of individual patient data from all known randomized trials has shown that CCM provides statistically significant and clinically meaningful benefits in measures of functional capacity and HF-related quality of life
Discovery of a single faint AGN in a large sample of z > 5 Lyman break galaxies
No full textAs part of a large spectroscopic survey of z > 5 Lyman break galaxies (LBGs), we have identified a single source which is clearly hosting an active galactic nucleus (AGN). Out of a sample of more than 50 spectroscopically confirmed R-band dropout galaxies at z∼ 5 and above, only J104048.6−115550.2 at z= 5.44 shows evidence for a high ionization potential emission line indicating the presence of a hard ionizing continuum from an AGN. Like most objects in our sample the rest-frame-UV spectrum shows the UV continuum breaking across a Lyα line. Uniquely within this sample of LBGs, emission from N V is also detected, a clear signature of AGN photoionization. The object is spatially resolved in Hubble Space Telescope (HST) imaging. This, and the comparatively high Lyα/N V flux ratio indicates that the majority of the Lyα (and the UV continuum longward of it) originates from stellar photoionization, a product of the ongoing starburst in the LBG. Even without the AGN emission, this object would have been photometrically selected and spectroscopically confirmed as a Lyman break in our survey. The measured optical flux (IAB= 26.1) is therefore an upper limit to that from the AGN and is of order 100 times fainter than the majority of known quasars at these redshifts. The detection of a single object in our survey volume is consistent with the best current models of high redshift AGN luminosity function, providing a substantial fraction of such AGN is found within luminous starbursting galaxies. We discuss the cosmological implications of this discovery
The author, the text, and the (post)critic: notes on the encounter between postcritique and postcolonial criticism
No full textThe article confronts postcolonial criticism with postcritique, a proposal by Rita Felski for a hermeneutic strategy aiming to overcome the limits of critique. Because of its self-reflexivity, its liaison with poststructuralism, and the societal categories it mobilizes, postcritics often see postcolonial criticism as a quintessential example of critique. However, postcolonial authors share similar concerns as postcritics, particularly when warning against any hasty conflation between intellectual work and political commitment. This article argues that the postcritical understanding of critique eschews the connection between critique and the realm of culture, thereby running the risk of doing away with context altogether. In order to account for the frameworks or contexts in which cultural objects are produced, without falling into some of the pitfalls of critique that postcritique aims to counter, the article proposes to look at the figure of the author as a bridge between the individual and the collective, as Edward Said suggests. The article closes with an analysis of several (critical and postcritical) readings of J. M. Coetzee’s The Childhood of Jesus to provide an example of how authorship can enter the interpretive scene through the figure of ‘late style’
Exploring the roles, effectiveness and impact of health information professionals within evidence based practice
No full textThis is the thesis (critical appraisal) component of a PhD by Published Works. The overall submission was a portfolio of ten published papers supported by a critical appraisal focusing on two key areas: an exploration of the roles that Health Information Professionals (HIPs) can play within evidence based practice (EBP) and an exploration of the effectiveness and impact of the traditional supportive role played by HIPs within EBP. The published papers are listed and referenced within this document but not contained within it. The majority are available elsewhere within the University of Salford Institutional Repository.Drawing on a model developed from the library literature, the thesis highlights a wide range of supportive and active roles that HIPs can potentially play within EBP. This model is informed and illuminated by the studies within the portfolio that demonstrate how the author has fulfilled a wide range of these roles in practice, and identified a new role within systematic reviews in health and social care. This demonstrates that HIPs can transfer their skills outside their traditional library and information practice domain, thus extending theirrole and offering a range of professional opportunities.Using a varied range of research methodologies, the thesis also explores the effectiveness and impact of the contribution made by HIPs when using traditional skills to support EBP. Two models are used to illustrate the outcomes to which HIPs contribute. These include improving search skills and providing evidence which can, over the longer term, contribute to policy making and patient care. At present the weight of the evidence presented tosupport these links is weak. Methodological issues and future research that needs to be addressed to improve the strength of the evidence base are therefore highlighted and discussed
The development of a taxonomy to support goal setting between mental health consumers and community pharmacists
No full textBackground: Goal setting is widely used in mental healthcare, yet there is limited information about goal development between community pharmacists and people experiencing mental health conditions. Objectives: i) To review goals developed in partnership between Australian community pharmacists and people experiencing depression/anxiety, and ii) categorize goals and develop a taxonomy. Methods: Community pharmacists (n = 142) who had completed a mental health training program provided an individualized medication support service and documented goal planning for 350 people experiencing anxiety and/or depression. Goals were reviewed using a general inductive content analysis to develop themes which were then grouped, categorized, and coded. This involved three researchers in different phases of the coding, repeated review and redrafting of the taxonomy, and inter-rater reliability consistency checks. Results: The goals (n = 749) represented a diverse range of health behaviors and outcomes (e.g., medication adherence, relationships, leisure activities). The resulting taxonomy involved five overarching domains: improved health; satisfaction with life; manage physical illnesses; manage mental health; and use of medicines. Conclusions: Pharmacists have a role in providing person-centered care and addressing social determinants of health by considering factors that contribute to a person's overall wellbeing. While further testing is necessary, the taxonomy is valuable for pharmacists unfamiliar with supporting goal development with people experiencing anxiety and/or depression.Full Tex
The XMM-Newton long look of NGC 1365: uncovering of the obscured X-ray source
No full textWe present an analysis of the extreme obscuration variability observed during an XMM–Newton 5-d continuous monitoring of the active galactic nuclei (AGN) in NGC 1365. The source was in a reflection-dominated state in the first ∼1.5 d, then a strong increase in the 7–10 keV emission was observed in ∼10 h, followed by a symmetric decrease. The spectral analysis of the different states clearly shows that this variation is due to an uncovering of the X-ray source. From this observation, we estimate a size of the X-ray source DS < 1013 cm, a distance of the obscuring clouds R∼ 1016 cm and a density n∼ 1011 cm−3. These values suggest that the X-ray absorption/reflection originates from the broad-line region clouds. This is also supported by the resolved width of the iron narrow Kα emission line, consistent with the width of the broad Hβ line
Galaxy Zoo:chiral correlation function of galaxy spins
No full textGalaxy Zoo is the first study of nearby galaxies that contains reliable information about the spiral sense of rotation of galaxy arms for a sizeable number of galaxies. We measure the correlation function of spin chirality (the sense in which galaxies appear to be spinning) of face-on spiral galaxies in angular, real and projected spaces. Our results indicate a hint of positive correlation at separations less than ~0.5 Mpc at a statistical significance of 2-3 sigma. This is the first experimental evidence for chiral correlation of spins. Within tidal torque theory it indicates that the inertia tensors of nearby galaxies are correlated. This is complementary to the studies of nearby spin axis correlations that probe the correlations of the tidal field. Theoretical interpretation is made difficult by the small distances at which the correlations are detected, implying that substructure might play a significant role, and our necessary selection of face-on spiral galaxies, rather than a general volume-limited sample
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